The aim of the research is to delineate the mechanisms involved in the formation of the senile type of cataract. The approach is to study biochemical and morphological changes in animal lenses and correlate such observations with changes observed in human senile cataract. The major hypothesis of the laboratory is that oxidative insult may be an initiating or early event contributing to cataract formation. Examination of defense systems against oxidative insult are being conducted. Studies are in progress upon Na/K ATPase, Ca ATPase and other transport systems; membrane structure, high molecular weight covalently linked protein aggregates; H2O2, photochemical and hyperbaric O2 effects on transport, metabolism and protein and lipid fractions of the lens; changes in cytoskeleton structure with aging and cataract formation, effects of oxidation on the molecular biology of the tissue and expression of gamma crystallin; polyamine interactions, phosphorylation and Ca++ effects on molecular structure. Bio-physical studies of protein denaturation induced by oxidative insult are also under investigation. In all cases study of human lenses both normal and cataract, classified by CCRG procedures are ongoing. The use of the PROPHET system to analyze data is an integral part of our procedures. This application is specifically to support, collection and classification of human material and to cover expenses involved with analysis of data by the PROPHET system.